Phosphodiesterases (PDEs) are a class of intracellular enzymes involved in the hydrolysis of the nucleotides cyclic adenosine monophosphate (cAMP) and cyclic guanosine monophosphates (cGMP) into their respective nucleotide monophosphates. The cyclic nucleotides cAMP and cGMP are synthesized by adenylyl and guanylyl cyclases, respectively.
The cAMP and cGMP function as intracellular second messengers regulating a vast array of intracellular processes particularly in neurons of the central nervous system. In neurons, this includes the activation of cAMP and cGMP-dependent kinases and subsequent phosphorylation of proteins involved in acute regulation of synaptic transmission as well as in neuronal differentiation and survival. The complexity of cyclic nucleotide signaling is indicated by the molecular diversity of the enzymes involved in the synthesis and degradation of cAMP and cGMP.
There are at least ten families of adenylyl cyclases, two of guanylyl cyclases, and eleven of phosphodiesterases. Furthermore, different types of neurons are known to express multiple isozymes of each of these classes, and there is good evidence for compartmentalization and specificity of function for different isozymes within a given neuron.
A principal mechanism for regulating cyclic nucleotide signaling is by phosphodiesterase-catalyzed cyclic nucleotide catabolism. There are 11 known families of PDEs encoded by 21 different genes. Each gene typically yields multiple splice variants that further contribute to the isozyme diversity. The PDE families are distinguished functionally based on cyclic nucleotide substrate specificity, mechanism(s) of regulation, and sensitivity to inhibitors. Furthermore, PDEs are differentially expressed throughout the organism, including in the central nervous system. As a result of these distinct enzymatic activities and localization, different PDEs' isozymes can serve distinct physiological functions. Furthermore, compounds that can selectively inhibit distinct PDE families or isozymes may offer particular therapeutic effects, fewer side effects, or both.
PDE10 is identified as a unique family based on primary amino acid sequence and distinct enzymatic activity. Homology screening of EST databases revealed human PDE10A as the first member of the PDE10 family of PDEs (Fujishige et al., J. Biol. Chem., 274, 18438-18445, 1999; Loughney, K. et al., Gene, 234, 109-117, 1999). The murine homologue has also been cloned (Soderling, S. et al., Proc. Natl. Acad. Sci. USA, 96, 7071-7076, 1999) and N-terminal splice variants of both the rat and human genes have been identified (Kotera, J. et al., Biochem. Biophys. Res. Comm., 261, 551-557, 1999; Fujishige, K. et al., Eur. J. Biochem., 266, 1118-1127, 1999). There is a high degree of homology across species. The mouse PDE10A1 is a 779 amino acid protein that hydrolyzes both cAMP and cGMP to AMP and GMP, respectively. The affinity of PDE10 for cAMP (Km=0.05 μM) is higher than for cGMP (Km=3 μM). However, the approximately 5-fold greater Vmax for cGMP over cAMP has lead to the suggestion that PDE10 is a unique cAMP-inhibited cGMPase (Fujishige et al., J. Biol. Chem., 274, 18438-18445, 1999).
PDE10A also is uniquely localized in mammals relative to other PDE families. mRNA for PDE10 is highly expressed only in testis and brain (Fujishige, K. et al., Eur J Biochem., 266, 1118-1127, 1999; Soderling, S. et al., Proc. Natl. Acad. Sci., 96, 7071-7076, 1999; Loughney, K. et al., Gene, 234, 109-117, 1999).
These initial studies indicated that within the brain PDE10A expression is highest in the striatum (caudate and putamen), n. accumbens, and olfactory tubercle. More recently, a detailed analysis has been made of the expression pattern in rodent brain of PDE10 mRNA (Seeger, T. F. et al., Abst. Soc. Neurosci., 26, 345.10, 2000) and PDE10 protein (Menniti, F. S., Stick, CA1 Seeger, T. F., and Ryan, A. M., Immunohistochemical localization of PDE10 in the rat brain, William Harvey Research Conference ‘Phosphodiesterase in Health and Disease’, Porto, Portugal, Dec. 5-7, 2001).
PDE10A was shown to be highly expressed in retinal neurons including photoreceptors. The levels of PDE10A transcript and protein display daily rhythms which could be seen in preparations of the whole retina (Wolloscheck T. et al, Brain Res., 2011, 1376, 42-50. Epub 2010 Dec. 29). These findings place PDE10A in the context of the visual system and suggest an important role of PDE10A in the adaptation of cyclic nucleotide signalling to daily changes in light intensity in retinal neurons including photoreceptors.
The tissue distribution of PDE10A indicates that PDE10A inhibitors can be used to raise levels of cAMP and/or cGMP within cells that express the PDE10 enzyme, especially neurons that comprise the basal ganglia, and the PDE10A inhibitors of the present invention would therefore be useful in treating a variety of associated neuropsychiatric conditions involving the basal ganglia such as neurological and psychiatric disorders, schizophrenia, bipolar disorder, obsessive compulsive disorder, and the like, and may have the benefit of not possessing unwanted side effects, which are associated with the current therapies on the market.
US 2003/0032579 discloses a method for treating certain neurologic and psychiatric disorders with the PDE10A inhibitor papaverine. In particular, the method relates to psychotic disorders such as schizophrenia, delusional disorders and drug-induced psychosis; to anxiety disorders such as panic and obsessive-compulsive disorder; and to movement disorders including Parkinson's disease and Huntington's disease. Other indications which may be treated using a PDE10A inhibitor are described in WO 20055120514.
A variety of therapeutic uses for PDE inhibitors has been reported including obtrusive lung disease, allergies, hypertension, angina, congestive heart failure, depression and erectile dysfunction (WO 2001041807, incorporated herein by reference). Furthermore, publications (WO 2005120514, WO 2005012485, Cantin et al., Bioorg. & Med. Chem. Lett., 17, 2869-2873, 2007) suggest that PDE10A inhibitors may be useful for treatment of obesity and non-insulin dependent diabetes.
WO 2011110545, WO 2011051342 (Janssen Pharmaceutica NV) disclose respectively imidazo[1,2-a]pyrazine derivatives, imidazo[1,2-b]pyridazine derivatives PDE10A inhibitors useful for the treatment or prevention of neurological, psychiatric and metabolic disorders in which the PDE10 enzyme is involved.
WO 2012007006, WO 2012000519, WO 2011072695, WO 2011072697, WO 2011072694, WO 2011072696, WO 2010145668 (H. Lundbeck A/S) disclose respectively triazolo- and pyrazoloquinazoline derivatives, aryl- and heteroarylamid derivatives, phenylimidazole derivatives comprising an ethynylene linker, heteroaromatic aryl triazole derivatives, heteroaromatic phenylimidazole derivatives, 2-arylimidazole derivatives, novel phenylimidazole derivatives as PDE10A inhibitors reported to be useful for the treatment of psychiatric and neurodegenerative disorders including schizophrenia as well as bipolar disorders, anxiety, stress disorders and Alzheimer's, Parkinson's and Huntington's disease, dementia and attention deficit/hyperactivity disorder.
WO 2011150156 (Sunovion Pharmaceuticals Inc.) discloses heteroaryl compounds as PDE10A inhibitors useful for the treatment, prevention, and/or management of various disorders, such as CNS disorders and metabolic disorders, including, but not limited to, e.g., neurological disorders, psychosis, schizophrenia, obesity, and diabetes.
WO 2010138833 (Biotie Therapies GmbH—Wyeth) discloses substituted imidazo[1,5-a]quinoxalines as PDE10A inhibitors useful in treating central nervous system diseases such as psychosis and also in treating, for example, obesity, type 2 diabetes, metabolic syndrome, glucose intolerance, and pain.
WO 2011053559 or WO 2011022213 or WO 2010138430 and WO 2010138585 or WO 2010138430 (Merck & Co., Inc.) disclose respectively aryl or amino or alkoxy tetrahydro-pyridopyrimidine derivatives or pyrimidinones as PDE10A inhibitors useful for the treatment of neurological and psychiatric disorders including schizophrenia, delusional disorders, drug induced psychosis, anxiety, movement, mood and neurodegenerative disorders.
WO 2010138577 (Merck & Co., Inc.) discloses radiolabeled pyrimidinone compounds which are useful as radiotracers for quantitative imaging of PDE10A in mammals.
WO 2011138657, WO 2011132051, and WO 2011132048 (Glenmark Pharmaceuticals SA) disclose respectively aryl substituted olefinic compounds, tricyclic compounds, and heteroaryl compounds as PDE10A inhibitors reported to be useful for the treatment of schizophrenia.
WO 2011163355 & WO 2010090737 (Takeda Pharmaceutical Co., Ltd.) disclose respectively fused heterocyclic compounds and pyridazinone compounds as PDE10A inhibitors useful for the treatment of schizophrenia.
WO 2010128995 (EnVivo Pharmaceuticals, Inc.) discloses phenoxymethyl heterocyclic compounds as PDE10A inhibitors useful for the treatment of schizophrenia, bipolar disorder, Huntington's disease, obesity and metabolic syndrome, among other disorders.
WO 2010117926 (Schering Corp.) discloses substituted triazolopyridines and analogs thereof as PDE10A inhibitors reported to be useful for the treatment of schizophrenia, psychosis, Alzheimer's disease, bipolar disorder, depression, obesity, diabetes and metabolic syndrome.
WO 2011051324 and WO 2010097367 (Janssen Pharmaceutica NV) disclose radiolabeled fluorinated azole PDE10A ligands reported to be useful in positron emission tomography imaging and quantification of PDE10A enzymes.
WO 2011117264, WO 2011089132 & WO 2011154327, WO 2011036127, and WO 2010094762 & WO 2010063610 (F. Hoffmann-La Roche AG) disclose respectively N-(imidazopyrimidin-7-yl)-heteroarylamide derivatives, nitrogen-containing heteroaryl derivatives, novel imidazopyridines, and heteroaryl substituted pyridazinone derivatives as PDE10A inhibitors reported to be useful for the treatment of schizophrenia, cognitive disorders, anxiety, substance abuse and dependence, Parkinson's disease, mood disorders, neurodegenerative disorders, stroke, diabetes and cancer, among other disorders.
WO 2011143366, WO 2011143365, WO 2011143495, WO 2010077992, and WO 2010057126 (Amgen Inc.) disclose respectively heteroaryloxycarbocyclyl compounds, nitrogen heterocyclic compounds, heteroaryloxyheterocyclyl compounds, aminopyridine and carboxypyridine compounds, and pyridine and pyrimidine derivatives as PDE10A inhibitors that are considered to have potential in the treatment of psychiatric disorders such as schizophrenia, bipolar disorder, obsessive-compulsive disorder, obesity, non-insulin dependent diabetes.
WO 2010062559 (Schering Corp.) discloses substituted pyrazoloquinolines and derivatives thereof as PDE10A inhibitors for the treatment of PDE10-modulated disorders.
WO 2010138833, WO 2010054253 & WO 2010054260 (Biotie Therapies GmbH—Wyeth) disclose respectively substituted imidazo[1,5-a]quinoxalines and triazine derivatives as inhibitors of phosphodiesterases, particularly PDE10A and PDE2A, described as useful for the treatment of pain, cognitive disorders, diabetes, obesity, extrapyramidal disorders, epilepsy and psychiatric disorders such as depression, anxiety, schizophrenia and attention deficit/hyperactivity disorders.
JP 2011201873, WO 2011105628, and WO 2010027097 (Mitsubishi Tanabe Pharma Corp.) disclose respectively trisubstituted pyrimidine compounds, pyrazolopyrimidine compounds, and tri-substituted pyrimidine compounds and their use as PDE10A inhibitors reported to be useful for the treatment of schizophrenia, anxiety, drug addiction, cognitive and mood disorders.
WO 2011112828 and WO 2010017236 (Omeros Corp.) disclose PDE10A inhibitors described as useful for the treatment of neurological and psychiatric disorders such as schizophrenia and post-traumatic stress disorder as well as Parkinson's disease, Huntington's disease, Alzheimer's disease, encephalitis, phobias, epilepsy, pain, sleep disorders, bipolar disorder and multiple sclerosis.
US 2010016303 & WO 2009152825 (H. Lundbeck NS) disclose novel phenylimidazole derivatives as PDE10A enzyme inhibitors to be useful in the treatment of psychiatric and neurological disorders such as schizophrenia, cognition deficits, Parkinson's disease, Alzheimer's disease, Huntington's disease and substance abuse, among others.
WO 2010006130 (EnVivo Pharmaceuticals, Inc.) discloses vicinal substituted cyclopropyl compounds as PDE10A inhibitors.
WO 2009158473, WO 2009158467 & WO 2009158393 (EnVivo Pharmaceuticals, Inc.) disclose respectively 5- and 6 membered heterocyclic compounds, disubstituted phenyls compounds and 1,2-disubstituted heterocyclic compounds as PDE10A inhibitors described as useful for the treatment of schizophrenia, Huntigton's disease, obesity and metabolic syndrome.
WO 2009070583 (Wyeth) discloses pyrido(3,2-e)pyrazines as inhibitors of PDE10A that are considered to have potential in the treatment of psychosis, mood diseases, anxiety, neurodegenerative disorders, obesity, diabetes, metabolic diseases, pain.
WO 2009068320 & WO 2009070584 (Biotie Therapies GmbH) disclose aryl and heteroaryl fused imidazo(1,5-a)pyrazines as inhibitors of PDE10A that are active compounds for treating central nervous system diseases of mammals, including humans.
WO 2009152825 & WO 2009036766 (H. Lundbeck NS) disclose respectively novel phenylimidazole derivatives and cyanoisoquinoline derivatives as PDE10A inhibitors.
WO 2009143178, WO 2008064342 & US 2008300240 (Omeros Corp.) disclose quinoline derivatives as PDE10A inhibitors active in psychotic, anxiety, movement disorders and/or neurological disorders such as Parkinson's disease, Huntington's disease, Alzheimer's disease, encephalitis, phobias, epilepsy, aphasia, Bell's palsy, cerebral palsy, sleep disorders, pain, Tourette syndrome, schizophrenia, delusional disorders, drug-induced psychosis and panic and obsessive-compulsive disorders.
WO 2009025839 & WO 2009025823 (Amgen Inc.) disclose cinnoline derivatives as PDE10A inhibitors that are considered to have potential in the treatment of psychiatric disorders such as schizophrenia, bipolar disorder and obsessive-compulsive disorder.
WO 2009029214 (Amgen Inc.—Memory Pharmaceuticals Corp.) discloses isoquinolone derivatives as PDE10A inhibitors that are considered to have potential in the treatment of schizophrenia, bipolar disorder, obsessive-compulsive disorder, obesity and diabetes.
WO 2008032171 (Matrix Laboratories Ltd.) discloses dibenzofuran as inhibitors of PDE4 and PDE10A with potential utility in the treatment of asthma, chronic obstructive pulmonary disease, allergic rhinitis, atopic dermatitis, multiple sclerosis, Huntington disease, Alzheimer's disease, Parkinson's disease, schizophrenia and depression, among other disorders.
WO 2008020302 (Pfizer Products Inc.) discloses heteroaromatic quinoline-based compounds as selective PDE10A inhibitors.
WO 2008006372 (H. Lundbeck NS) discloses 6,7-dialkoxyquinazoline and 6,7-dialkoxyisoquinoline derivatives as PDE10A inhibitors that are considered to have potential in the treatment of psychiatric and neurological disorders such as schizophrenia, cognition deficits, Parkinson's disease, Alzheimer's disease, dementia, epilepsy, multiple sclerosis and Huntington's diseases.
WO 2008004117 & WO 2006072828 (Pfizer Products Inc.) disclose respectively selective azole compounds and heteroaromatic quinoline compounds as PDE10A inhibitors that are considered to have potential in the treatment of psychotic, anxiety, movement, mood and neurodegenerative disorders and obesity.
WO 2007137819 & WO 2007137820 (Biotie Therapies GmbH) disclose respectively 4-amino-pyrido(3,2-e)pyrazines and pyrido(3,2-e)pyrazines as PDE10A inhibitors. More particularly, the inventions relate to the treatment of neurologic and psychiatric disorders, for example psychosis and disorders comprising cognitive deficits as symptoms.
WO 2007103370, WO 2007103260, WO 2007100880 & WO 2007022280 (Amgen Inc.—Memory Pharmaceuticals Corp.) disclose quinazoline derivatives as PDE10A inhibitors that are considered to have potential in the treatment of schizophrenia, bipolar disorder and obsessive-compulsive disorder. Further applications include obesity and non-insulin diabetes.
WO 2007103554, WO 2007098214 & WO 2007098169 (Amgen Inc.—Memory Pharmaceuticals Corp.) disclose cinnoline derivatives as PDE10A inhibitors that are considered to have potential in the treatment psychiatric disorders such as schizophrenia, bipolar disorders and obsessive-compulsive disorder.
WO 2007096743 & WO 2007085954 (Pfizer Products Inc.) disclose respectively substituted quinazolines and aminophthalazine compounds as PDE10A inhibitors that are considered to have potential in the treatment of psychotic disorders, anxiety disorders, movement disorders such as Parkinson and Huntington diseases, mood disorders, obesity and drug addiction.
WO 2006089815 & WO 2006075012 (Nycomed GmbH) disclose novel pyrrolodihydroisoquinolines as PDE10A inhibitors with potential utility in the treatment of neurological and psychiatric disorders, in diabetes therapy and in the regulation of fertility.
WO 2006071988 & WO 2006028957 (Memory Pharmaceuticals Corp.) disclose respectively thienopyrimidine derivatives and 4-substituted-4,6-dialkoxy-cinnoline derivatives as PDE10A inhibitors that are considered to have potential in the treatment of psychosis, including schizophrenia, bipolar disorder and obsessive-compulsive disorder, Alzheimer's disease and movement disorders such as Parkinson's disease. Other conditions include epilepsy, multiple sclerosis, Huntington's disease, disorders relating to the basal ganglia, diabetes and obesity.
WO 2006070284 & WO 2006011040 (Pfizer Products Inc.) disclose respectively pyrrolidyl derivatives of heteroaromatic compounds, and quinazolin-4-yl-piperidine and cinnolin-4-yl derivatives as PDE10A inhibitors that are considered to have potential in the treatment of CNS disorders, including schizophrenia, delusional disorders, drug-induced psychosis, anxiety, mood and movement disorders, neurodegenerative disorders and drug addiction.
WO 2005082883 (Pfizer Products Inc.) discloses tetrahydroisoquinolinyl derivatives of quinazoline and isoquinoline as PDE10A inhibitors that are claimed for use in the treatment of psychotic disorders, anxiety and movement disorders including Parkinson's disease and Huntington's disease, among other conditions.
WO 2006034512 & WO 2006034491 (Bayer Pharmaceuticals Corp.) disclose PDE10A inhibitors described as useful for the treatment of diabetes and related disorders. Pyrrolodihydroisoquinolines and variants thereof are disclosed as inhibitors of PDE10A in WO 2005003129 and WO 2005002579 (Nycomed GmbH).
WO 2004005291 & WO 2004005290 (Bayer Healthcare AG) disclose hetero-cyclically substituted imidazotriazines as PDE10A inhibitors described as useful for the treatment of neurodegenerative conditions, particularly Parkinson's disease and schizophrenia, and cancer.
WO 2004002484 (Kyowa Hakko Kirin Co., Ltd.) discloses quinoline derivatives as PDE10A inhibitors with potential in the treatment of Parkinson's disease, dyskinesia, anxiety, stress, mood and cognitive disorders, drug abuse, schizophrenia, cerebrovascular disorders, erectile dysfunction, diabetes, ischemic cardiopathies, renal disorders, peripheral vascular disease, hypertension, urinary incontinence, autoimmune diseases, respiratory disorders, allergies, pain, osteoporosis, cancer.
WO 2003014116 (Bayer Healthcare AG) discloses pyrrolo[2.1-a]isoquinoline derivatives as PDE10A inhibitors with potential in the treatment of cancer. WO 2003000693 (Bayer Healthcare AG) discloses imidazotriazines for use as PDE10A inhibitors considered to have potential in the treatment of Parkinson's disease.
All the above-mentioned publications are incorporated herein by reference.
However, these disclosures do not pertain to the compounds of the invention, which are structurally unrelated to any of the known PDE10A inhibitors (Kehler, J. et al., Expert Opin. Ther. Patents, 17, 147-158, 2007 and above cited patent literature), and which have now been found by the inventors to be highly active and selective PDE10A enzyme inhibitors.
The compounds of the invention offer alternatives to current marketed treatments for neurodegenerative and/or psychiatric disorders, which are not efficacious in all patients.